This invention relates to a cylinder lock assembly, and in particular an automotive ignition lock cylinder having a lock cylinder that is axially and rotatably movable in an inner core of a cylindrical lock housing.
A prior art ignition lock assembly, shown in FIG. 1, for use in a vehicle includes a cylindrical lock housing having an inner core that receives a lock cylinder. The lock cylinder includes a key slot for receiving a key that engages tumblers housed in the lock cylinder. A spring biased rotation plate, or actuator, is retained in a radial slot formed in the lock cylinder by a rotation ring. A snap ring engaging an end of the lock cylinder retains the lock cylinder in the housing. The lock cylinder is axially movable in the lock housing to actuate an electrical device, such as a switch, and/or a mechanical device, such as a steering column lock, and is rotatable to actuate the vehicle ignition.
The prior art ignition lock assembly is operated by inserting a key into the key slot of the lock cylinder. Upon entry of the key into the key slot, the leading end of the key engages the rotation plate which prevents full insertion of the key into the key slot. The user must urge the rotation plate, and thus the entire lock cylinder, axially forward until the rotation plate is aligned with an opening formed adjacent the rotation ring. Upon alignment of the rotation plate with the opening, the rotation plate is urged radially into the rotation ring opening by a spring to lock the lock cylinder in an axially forward position and clear the key slot for further insertion of the key into the key slot. Unfortunately, the force required to urge the lock cylinder axially forwardly is annoying and detracts from the image of certain luxury vehicles.